Ferroelectricity and Ferroelasticity in Organic Inorganic
Hybrid (Pyrrolidinium)<sub>3</sub>[Sb<sub>2</sub>Cl<sub>9</sub>]
Martyna Wojciechowska
Anna Gągor
Anna Piecha-Bisiorek
Ryszard Jakubas
Agnieszka Ciżman
Jan K. Zaręba
Marcin Nyk
Piotr Zieliński
Wojciech Medycki
Andrzej Bil
10.1021/acs.chemmater.8b00962.s004
https://acs.figshare.com/articles/media/Ferroelectricity_and_Ferroelasticity_in_Organic_Inorganic_Hybrid_Pyrrolidinium_sub_3_sub_Sb_sub_2_sub_Cl_sub_9_sub_/6771698
Perovskite-like materials
exhibit desirable photophysical and electric
properties that make them suitable for a remarkable breadth of applications
in electronics and physics. In this contribution, we report on the
multiphase ferroelectric and ferroelastic phenomena in a pyrrolidinium-based
hybrid metal–organic material: (C<sub>4</sub>H<sub>8</sub>NH<sub>2</sub>)<sub>3</sub>[Sb<sub>2</sub>Cl<sub>9</sub>]. The title compound
is the first pyrrolidinium derivative within the halobismuthates(III)
and haloantimonates(III) families that is featured by the ferroelectric
property. From a structural point of view, the crystal structure is
built of [Sb<sub>2</sub>Cl<sub>9</sub>]<sup>3–</sup><sub>∞</sub> perovskite-like layers, interdigitated by layers of pyrrolidinium
cations. The rich solid-state dynamics of pyrrolidinium cations endowed
(C<sub>4</sub>H<sub>8</sub>NH<sub>2</sub>)<sub>3</sub>[Sb<sub>2</sub>Cl<sub>9</sub>] with a complex sequence of temperature-dependent
phase transitions. Remarkably, polar properties have been found to
occur in all six phases, including room-temperature Phase I. Insights
from variable-temperature single-crystal X-ray diffraction, dielectric
spectroscopy, and T<sub>1</sub> spin–lattice relaxation measurements
revealed the general mechanism of most phase transitions, as related
to the progressive ordering of nonequivalent pyrrolidinium cations.
Noncentrosymmetry is probed by room-temperature second harmonic generation
(SHG), while the ferroelectric property was evidenced through <i>P</i>(<i>E</i>) and dielectric measurements. The experimental
values of spontaneous polarization were justified and analyzed in
the context of theoretical values derived from quantum-chemical calculations.
Optical measurements show that the integrity of the sample survives
all of the phase transitions, despite sometimes significant deformations
of the unit cell. The changes of symmetry associated with structural
phase transitions are accompanied by an intriguing evolution of the
ferroelastic domain structure with temperature.
2018-06-22 00:00:00
room-temperature
pyrrolidinium cations
dielectric
Optical measurements show
variable-temperature single-crystal X-ray diffraction
C 4 H 8 NH 2
Sb 2 Cl 9
SHG
phase transitions
Perovskite-like materials exhibit
temperature-dependent phase transitions
ferroelastic domain structure